Final answer:
According to ASHRAE's 1992 refrigerant safety classification, the most safe designation would be A-1.
Step-by-step explanation:
According to ASHRAE's 1992 refrigerant safety classification, the most safe designation would be A-1.
The ASHRAE refrigerant safety classification categorizes refrigerants into three groups: A, B, and C. Group A represents low toxicity and no flame propagation, while Group B represents higher toxicity and low flame propagation. Within each group, there are subcategories indicated by a number. The lower the number, the safer the refrigerant. A-1 is the safest designation in Group A, indicating low toxicity and no flame propagation, making it the best choice in terms of safety.